Merge remote-tracking branch 'remotes/kevin/tags/for-upstream' into staging

Block layer patches

# gpg: Signature made Wed 30 Mar 2016 11:57:54 BST using RSA key ID C88F2FD6
# gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>"

* remotes/kevin/tags/for-upstream: (48 commits)
  iotests: Test qemu-img convert -S 0 behavior
  block/null-{co,aio}: Implement get_block_status()
  block/null-{co,aio}: Allow reading zeroes
  qemu-img: Fix preallocation with -S 0 for convert
  block: Remove bdrv_(set_)enable_write_cache()
  block: Remove BDRV_O_CACHE_WB
  block: Remove bdrv_parse_cache_flags()
  qemu-io: Use bdrv_parse_cache_mode() in reopen_f()
  block: Use bdrv_parse_cache_mode() in drive_init()
  raw: Support BDRV_REQ_FUA
  nbd: Support BDRV_REQ_FUA
  iscsi: Support BDRV_REQ_FUA
  block: Introduce bdrv_co_writev_flags()
  block/qapi: Use blk_enable_write_cache()
  block: Move enable_write_cache to BB level
  block: Handle flush error in bdrv_pwrite_sync()
  block: Always set writeback mode in blk_new_open()
  block: blockdev_init(): Call blk_set_enable_write_cache() explicitly
  xen_disk: Call blk_set_enable_write_cache() explicitly
  qemu-img: Call blk_set_enable_write_cache() explicitly
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 12 insertions, 1 deletions

diff --git a/qemu-io-cmds.c b/qemu-io-cmds.c
index 139f7ebcbb..382faa8a2a 100644
--- a/qemu-io-cmds.c
+++ b/qemu-io-cmds.c
@@ -2106,6 +2106,7 @@ static int reopen_f(BlockBackend *blk, int argc, char **argv)
     QDict *opts;
     int c;
     int flags = bs->open_flags;
+    bool writethrough = !blk_enable_write_cache(blk);
 
     BlockReopenQueue *brq;
     Error *local_err = NULL;
@@ -2113,7 +2114,7 @@ static int reopen_f(BlockBackend *blk, int argc, char **argv)
     while ((c = getopt(argc, argv, "c:o:r")) != -1) {
         switch (c) {
         case 'c':
-            if (bdrv_parse_cache_flags(optarg, &flags) < 0) {
+            if (bdrv_parse_cache_mode(optarg, &flags, &writethrough) < 0) {
                 error_report("Invalid cache option: %s", optarg);
                 return 0;
             }
@@ -2138,6 +2139,14 @@ static int reopen_f(BlockBackend *blk, int argc, char **argv)
         return qemuio_command_usage(&reopen_cmd);
     }
 
+    if (writethrough != blk_enable_write_cache(blk) &&
+        blk_get_attached_dev(blk))
+    {
+        error_report("Cannot change cache.writeback: Device attached");
+        qemu_opts_reset(&reopen_opts);
+        return 0;
+    }
+
     qopts = qemu_opts_find(&reopen_opts, NULL);
     opts = qopts ? qemu_opts_to_qdict(qopts, NULL) : NULL;
     qemu_opts_reset(&reopen_opts);
@@ -2146,6 +2155,8 @@ static int reopen_f(BlockBackend *blk, int argc, char **argv)
     bdrv_reopen_multiple(brq, &local_err);
     if (local_err) {
         error_report_err(local_err);
+    } else {
+        blk_set_enable_write_cache(blk, !writethrough);
     }
 
     return 0;